Conventionally, known is a tire vulcanizer for vulcanizing a raw tire by supplying a high temperature and high pressure heating and pressurizing medium into the inner space of the raw tire housed inside a mold and thereby pressing the raw tire against the inner surface of the mold (for instance, refer to Patent Document 1).
The tire vulcanizer disclosed in Patent Document 1 comprises a medium path that is connected to the inner space of the raw tire housed in the mold, and the heating and pressurizing medium is supplied to the inner space of the raw tire through the medium path. In addition, a heater is provided to the medium path and the heating and pressurizing medium to be supplied to the inner space of the raw tire is preheated with the heater.
Meanwhile, as the heater, considered may be a configuration where a sheath heater is inserted into the piping of the medium path through which flows the heating and pressurizing medium, but with a heater that is configured as described above, there is a problem in that the rise in the temperature of the heating and pressurizing medium is delayed and the heat loss will increase.
Specifically, with this kind of heater, upon heating the heating and pressurizing medium, the heating wire of the sheath heater is foremost heated, and the heating and pressurizing medium is heated as a result of the foregoing heat being transferred to the heating and pressurizing medium via the insulator and sheath material of the sheath heater. Thus, the rise in the temperature of the heating and pressurizing medium will be delayed for the amount of thermal capacity of the sheath heater itself. In addition, with this kind of heater, it is necessary to increase the diameter of the piping in order to insert the sheath heater therein, and heat loss from the piping surface will consequently increase. Moreover, heat loss will also occur from the portion of the sheath heater that is positioned on the outside of the piping. Specifically, the overall heat loss will increase due to the foregoing types of heat loss.
Patent Document 1: Japanese Patent Application Laid-open No. 2005-22399